1. Field of the Invention
This invention relates to the field of composition of materials and articles that have one or more properties of the composition or article electrically induced and more particularly to chemical processes that can be electrically induced in electrorheological fluids and electroset materials.
2. Background Information
The invention disclosed herein is a continuation in part of work previously accomplished and for which copending patent applications were filed on Jul. 15, 1988 as Ser. Nos. 07/219,522 entitled Induced Dipole Electroviscous Fluids and 07/219,523 entitled Photoelectroviscous Fluids and on Sep. 11, 1989 as Ser No. 07/405,178 entitled Electroset Compositions and Articles and on Nov. 5, 1990 as Ser. No. 07/584,836 entitled Programmable Electroset Materials and Processes, the disclosures of which are hereby incorporated by reference. In particular, my earlier copending applications have disclosed electroviscous fluids and aggregates useful in electroviscous fluids. A later copending application disclosed a series of compounds utilizing, in part, the aggregates disclosed in my earlier copending applications. The term aggregate is used in the collective to include a multiplicity of electrically polarizable aggregate particles, said particles comprising the particulate of electrorheological fluids. In my copending applications, the term electroviscous aggregate has been used to describe an aggregate which, when placed in a dielectric fluid, causes the combination of fluid and aggregate to behave electroviscously. In my still later copending application and in this application, the term electrorheological aggregate is used in a similar manner.
U.S. Serial Nos. 07/405,178 and 07/584,836, have disclosed the second group of Reitz effects associated with the accelerated curing of electroset materials and the programming of electroset materials. At the time of filing co-pending application Ser Nos. 07/405,178 and 07/584,836, the effect of accelerating the cure of a compound and electrically programming into a compound desired physical and mechanical properties was known. It was not and still is not known, however, how such effects were manifest within these electroset materials. Furthermore, electroset materials are castable compounds that can harden into solid objects without the application of an electric field. Such art is limited to castable compounds only. The present invention is advantageous over the prior art in that chemical reactions within an electrorheological fluid can be controlled without the non-energized electrorheological fluid hardening into a solid object. In fact, the present invention can be employed in such a manner as to result in chemical products that are not solids even after an electric field has been applied to and then removed from the electrorheological fluid. This means that the electrorheological fluid which is intended to be used for chemical processing can be stored over long periods of time. Such electrorheological fluids can be stored for a long period of time and then later used for controlling chemical reactions and processes.
Prior art teaches that electrically induced polymerization of organic compounds can be accomplished within a monomer between charged electrode surfaces which are composed of substances which can form pi-complexes with organic compounds. Such processes, found in U.S. Pat. No. 3,629,083, are limited in that the monomer is placed in an inert atmosphere. Polymers resulting from the use of this process are formed only are a result of charges being extracted from the surface of the electrodes. They are not the result of charged particles, dipoles, ions and the like which form WITHIN the monomer.
Numerous teachings concerning chemical reactions are found in readily available references such as Chemistry authored by Gillespie, Humphreys, Baird and Robinson and published by Allyn and Bacon, Inc. of Boston, Mass. (copyright 1986); A Brief Review in Chemistry, authored by Patrick Kavanah and published by Cebco Standard Publishing of Fairfield, N.J. (3rd edition, copyright 1981); Organic Chemistry authored by Morrison and Boyd and published by Allyn and Bacon, Inc. of Boston, Mass. (3rd edition, copyright 1973) and Vitalized Chemistry authored by Henry Dorin and published by the College Entrance Book Company of New York, N.Y. (5th edition, copyright 1964). Prior art of corona and electric discharge attempts to treat materials wherein such chemical reactions occur are known and use of such processes are taught in U.S. Pat. Nos. 4,649,097; 4,966,666 and 4,940,894. While such teachings, processes and apparatus are useful, all are limited in that they form charges and ions that enter into the altered material from an origin external to the material. The charges and ions formed by discharge and corona processes are emitted from the energizing electrodes themselves and DO NOT originate from WITHIN the material to be processed and polymerized or formed. As a result, both the discharge processes and corona processes are severely limited as methods to electrically initiate or control chemical reactions within the material. These processes often require that the dielectric strength of the processed material be exceeded, thus resulting in a corona or a discharge due to dielectric breakdown. For this reason, enormous voltages are required for materials of significant thickness to be so formed. It is therefore impractical to employ such methods when electrically initiating or, alternatively, electrically controlling chemical reaction in a material of significant thickness.
Furthermore, the known corona and discharge processes cannot easily nor even effectively manipulate many intermolecular interactions which govern the results of many chemical reactions. As taught on pages 470 to 478 of Chemistry, many intermolecular forces involve the interaction between ions and dipoles, ions and dipoles induced by the presence of those ions, dipoles and dipoles, dipoles and other dipoles that are induced by the presence of the first dipoles, and the so-called London forces, a term which describes induced dipole-induced dipole interactions, said first induced dipoles and said second induced dipoles resulting from naturally occurring fluctuations within nonpolar molecules. All of these interactions are a result of electrostatic forces within the material.
Because there are so many nonpolar materials and intermolecular interactions that are possible in nature, it is desirable to have the means of effectively electrically controlling these interactions through the means of imposing an external electric field across these materials to initiate reactions and cause reactions WITHIN the materials. Known corona and electric discharge processes are ineffective because dipole-dipole interactive forces and induced dipole-induced dipole interactive forces have a 1/r 7 dependence on distance away from said dipoles. Their resultant electric fields are thus negligable at distances of 3 r, wherein r is distance from the midpoint of one dipole to the midpoint of another dipole. As a result, there is negligable affect in non-electrorheological fluid materials by imposition of an electric field across a material thickness of 3 rave or more wherein rave is the average distance between the midpoint of a dipole and its nearest neighbor dipole. Thus, establishment and control of an electric field across a non-electrorheological fluid of 3 rave thickness or more is ineffective for non-electrorheological fluids within which these dipole-dipole interactions and induced dipole-induced dipole interactions take place.
It is now known, however, that electrorheological fluids can solidify electrically BY THE CREATION OF INDUCED DIPOLES WITHIN THE FLUID due to the establishment of an electric field across said fluid by external means. The induced dipoles thus formed are established throughout the fluid material medium and are therefore in close enough proximity to other dipoles within the fluid medium to effect control of intermolecular chemical reactions therein.
It is well established in the science of chemistry that the extent to which a chemical reaction will proceed, the rate of the reaction and even the kind of chemical reaction that occurs is often appreciably affected by the solubility of one or more constituents in a composition.
The extent to which a material is soluble is often expressed in the well-known solubility constant which is taught on page 576 of Chemistry. It is also well established that the solubility of some materials is dependent upon the acidity (in pH) of a solution, which is taught in pages 577 to 584 of Chemistry. This reference further teaches that the precipitation of a salt from a solution can be selective by selecting an appropriate pH for a specific solution. Other examples of chemical reactions affected by the pH include reactions with aromatic rings (p. 751 of Organic Chemistry), the cleavage of ethers (p. 559 of Organic Chemistry), the coupling of diazonium salt and a phenol [or alternatively an amine] as taught on page 773 of Organic Chemistry, the rate of enzyme-catalyzed hydrolysis (p. 1167 of Organic Chemistry), the addition of certain derivatives of ammonia as taught in pages 639-640 of Organic Chemistry and dissolving (solubility) of carbonates as taught in page 581 of Chemistry.
Aromatic rings are activated toward electrophilic substitution by base-strengthening substituents and are deactivated toward electrophilic substitution by base weakening substituents. The cleavage of ethers (with the notable exception of epoxides) can only be accomplished with acids and NOT bases. The coupling of diazonium salt to a phenol can be successfully accomplished with the adjustment of the coupling medium to the right degree of acidity (i.e. the proper pH). Enzyme-catalyzed hydrolysis changes as the acidity of the reaction medium changes. Adjusting the reaction medium to just the right acidity is important to the addition of derivatives of ammonia.
Another example of a pH sensitive reaction is the Cannizzario reaction as taught in Organic Chemistry in sections 19.16 and 21.5 (3rd edition). These sections teach that Aldol condensation cannot take place if the aldehyde or ketone in the reaction does not contain an alpha-hydrogen. In a dilute base, there is no reaction. In concentrated base, however, they may undergo the Cannizzaro reaction.
It is, therefore, desirable to have a means of electrically controlling the pH of an electrorheological fluid or, alternatively, controlling the pH of the constituents of an electrorheological fluid. Such electrical control of pH may be used to control the solubility of constituents within an electrorheological fluid and thereby can control the resulting chemical reactions and products thereof.
It is taught in Vitalized Chemistry page 164 that the solubility of a salt in a specific solvent is dependent upon the polarizability of the solvent. To quote Dorin from page 164 of Vitalized Chemistry, "It is this polar property that accounts for the solvent power of water for so many substances." But this is only part of the story of solubility. In Chemistry, pages 481 to 484, it is taught that polar substances are soluble in polar liquids and that nonpolar substances are soluble in nonpolar liquids. "Like dissolves like" is taught in this reference.
It is also taught in application 07/219,522 that dipoles are induced or created in the particulate of an electroviscous fluid when an electric field is applied to said electroviscous fluid. The creation or induction of these dipoles does more than change the effective viscosity of the electroviscous (EV) fluid. It causes a polarization throughout the fluid and creates dipole charges within the electroviscous fluid.
An electroviscous fluid (also called electrorheological fluid) comprises a dielectric fluid and electrically polarizable particulate immersed within and suspended throughout said dielectric fluid. Applying a voltage to two electrodes in contact with an electroviscous fluid causes the electrical induction or formation of dipoles in or on the surface of said particulate or aggregate. The electroviscous fluid thus becomes "polarized", a condition which changes the overall solvent characteristics of the EV fluid.
Without the field inducing dipoles within the particulate or aggregate, the EV fluid would be much less polarized, and therefore, its overall solvent characteristics would be appreciably different than when it is electrically energized.
As taught on page 470 of Chemistry, there are interactions between ions and dipoles in some materials. These interactions have a dependence of force on distance of 1/r 3 where r is the distance between the center of the ion and the midpoint of the dipole. These dipoles are permanent dipoles which are characteristic of some of the constituents of the material wherein these intermolecular interactions occur.
It is noteworthy that ions within a material can induce dipoles in other nearby molecules. However, since these are ion induced, the ion-induced dipole interactive forces have a dependence of force on distance of 1/r 5 wherein r is the distance between the center of the ion and the midpoint of the dipole.
As taught in my prior application serial no. 07/219,522, dipoles can be induced within an electrorheological fluid by applying an electric field to said electrheological fluid. These induced dipoles are NOT those created by the presence of a nearby ion. They are created by immersing the electrorheological in an electric field of EXTERNAL origin such as the charging of electrodes between which is the electrorheological fluid. (This is possible in non-electrorheological fluids.) Because these induced dipoles are created by external means, the electrical forces associated with said induced dipoles can be made much stronger (with a 1/r 3 dependence) than those produced by the proximity of an ion. Thus, the strength of the electrical forces associated with the interaction of an ion and an externally created induced dipole within an electrorheological fluid can be used to effectively initiate (or, alternatively, to control) the interactions between ions and dipoles and between ions and induced dipoles. For example, the externally generated induced dipoles (i.e. those resulting from the application of an electric field to an electrorheological fluid) can be used to control the migration of ions within said electrorheological fluids. Thus, the concentration of ions within various regions of the electrorheological fluid can be easily manipulated to control chemical reactions within said electrorheological fluid. Such ion concentration manipulations in a non-electrorheological fluid are possible only in thin fluids. Manipulation of ion concentrations within non-electrorheological fluids requires prohibitively high electric fields and is, therefore, impractical.
Many chemical reactions are dependent upon the concentration of various constituents in the reaction. As taught on pages 82, 87 and 145 in A Brief Review in Chemistry (3rd edition), the concentration of chemical substances affects the rate of chemical reactions, the substances produced by chemical reactions and the chemical equalibrium conditions associated with chemical reactions.
It is, therefore, advantageous and desirable to electrically initiate (or alternatively, to control) ion-dipole interactions within an electrorheological fluid.
The present invention uses the polarizability of an electrorheological fluid, the induction of dipoles in the particulate (which is also called aggregate) of said electrorheological fluid and the ability to cause changes in the pH within the electrorheological fluid to control chemical processes occurring therein. Numerous chemical processes within an electrorheological fluid have been found to be affected by the electrical activation of an electrorheological fluid, some of which are discussed in the detailed description of the preferred embodiments of this disclosure. The present invention employs the electrical control of the polarizability of electrorheological (also called electroviscous) fluids and the ability to electrically control the pH of an electrorheological fluid in order to electrically control chemical reactions within said electrorheological fluid. The present invention employs the use of dipole induction within an electrorheological fluid to control ion migration and ion concentrations within said electrorheological fluid. It uses electrically controlled chemical reactions within an electrorheological fluid that can be stored for long periods of time without setting and curing. In this disclosure, the term "electrorheological" and "electroviscous" will be used interchangeably and refer to the same materials.